core

## Cylindricity

The Cylindricity form tolerance controls the shape of a cylinder feature without controlling the size, orientation, or location. The surface of the considered cylinder must lie within a tolerance zone bounded by two concentric cylinders whose radii differ by the specified tolerance value. Cylindricity controls the circularity, straightness, and taper of the considered cylinder. Material condition modifiers and datum features are not allowed.

(A) If your drawing has this. (B) It means this. (C) A .001 wide tolerance zone.

Checking Cylindricity

Considered Features: Measured Cylinder, Auto Cylinder, and Constructed Cylinder

1. From the Insert | Dimension menu, or from the Dimension toolbar, choose Cylindricity to display the XactMeasure GD&T dialog box.

2. From the Feature area, select at least one cylinder feature that contains at least six data points.

3. From the Feature Control Frame editor area, define the tolerance value for the Feature Control Frame (FCF).

4. Click Create to calculate the cylindricity dimension.

5. Click Close to close the XactMeasure GD&T dialog box.

6. View the results by opening the Status window (View | Other Windows | Status Window) or the Report window (View | Report Window). If the cylindrical feature fails the cylindricity tolerance, PC-DMIS colors the text red.

(A) The measured value is determined by calculating the minimum radial separation between two concentric cylinders that contains all of the measured surface points of the cylinder.

The cylinder passes the cylindricity tolerance if the measured value is within the tolerance value.